Internal-combustion engine



Sept. 1946. s, PARENT| 2,407,6$1

v INTERNAL-COMBUSTION ENGINE Filed Nov. 16, 1942 4 Sheets-Sheet 1INVENTOR Ja -177% 1.9. Pareflfz' ATTORNEYS P 17, J. s. PARENT!INTERNAL-COMBUSTION ENGINE Filed Nov. 16, 1942 4 Sheets-Sheet '2lNVENTQR Jase 9% 5372 7176 ATTORNEYS 4 Sheets-Sheet 3 yvna' ATTORNEYS p17, 4 J. 's. PARENTI INTERNAL-COMBUSTION ENGINE- Filed No v'. 16, 1942INVENTOR Jois'epz SEn-zzfc B Sept. 17, 1946. J. sfPARENTIINTERNAL-COMBUSTION ENGINE Filed Nov. 16, 1942 4 Sheets-Sheet 4YIVNVENTO'R N Jae v1? l a er??? I BY b w /gaauu PM ATTORNEYS PatentedSept. 17, 1946 UNITED STATES PATENT OFFICE INTERNAL-COMBUSTION ENGINEJoseph s. Parenti, Bufialo, N. Y. Application November 16, 1942, SerialNo. 465,944

17 Claims. 1

This invention relates to internal combustion engines.

One of the objects of this invention is to provide an internalcombustion engine of improved construction.

Another object of this invention is toprovide an engine of this typewith cylinders of improved and simplified construction. A further objectof this invention is toprovide anengine of this type having the headsthereof formed integral with the cylindrical portions thereof. A furtherobject of this invention is to provide an engine frame having cylindersmounted thereon for expansion and contraction independently of theengine frame. A further object is to provide the engine frame withjackets for a cooling fluid and extending about the cylinders, and withflexible heads which permit the cylinders to expand and contract withchanges in temperature.

It is also an object of this invention to provide an engine frameor-housing having cylinders with integral heads mounted therein and toprovide the engine frame with flexible heads of light metal spaced fromthe cylinder heads to form a jacket for cooling the fluid, the flexibleheads of the engine frame compensating for expansion and contraction ofthe cylinders.

It is also an object of this invention to provide an engine of this typeof novel construction, in

which the two opposed pistons may be inserted into the engine frame andafter their cylinders have been assembled thereon.

A further object of this invention is to provide an improved mechanismfor connecting the pistons of the engine with the shaft in such a mannerthat the piston is never in dead center relation to the shaft. Anotherobject of this invention is to provide an engine of this type in whichthe pistons are connected to the shaft by means of oscillatory rockerarms which are intermittently coupled to and uncoupled from the shaft. Afurther object is to provide accurate and reliable means for connectinga rocker arm to the shaft during a fraction of each rotation of theshaft and to disconnect the rocker arm from the shaft during anotherfraction of the rotation thereof. It is also an object of this inventionto provide the rocker arms with gear teeth which mesh with pinions onthe shaft, which pinions are alternately rotated about their axes andheld against such rotation. A further object of this invention is toprovide improved means for alternately holding the pinions againstrotation about their axes and releasing them. a

A further object of this invention is to provide an engine having a pairof opposed pistons which are alternately coupled to the shaft so thateither piston is always securely coupled to the shaft, the pistons alsobeing secured to each other. A

further object is to provide a coupling mecha-1 nism for'the engine bymeans of which thepistons may be reciprocated in their cylinders byrotation of the engine shaft. It is also an object of this invention toprovide a coupling mechanism for an engine which causes the pistons tobe moved through their entire strokes when the shaft is turned.

Other objects and advantages of this invention will appear from thefollowing description and claims. a a In the accompanying drawings:

Fig. 1 is a longitudinal central sectional elevation of an internalcombustion engine embodying this invention.

Fig. 2 is a longitudinal elevation thereof, partly in section, and takenat a right angle to the view shown in Fig. 1. v

Fig. 3 is a longitudinal sectional view thereof, on line 3-3, Fig. 2.

Fig. 4 is a transverse sectional view thereof, on line 4--4, Fig. 3.

Fig. 5 is a fragmentary transverse section thereof, on line 55, Fig, 1,on an enlarged scale.

Figs. 6 and '7 are fragmentary sectional elevations thereof, takenrespectively on lines 6-6 and 1--1, Fig. 5.

Fig. 8 is a diagrammatic view showing the cam portion of one of the gearshafts and a portion of the cam plate with which it cooperates, foralternately locking and releasing its gear against and for rotationabout its axis a The engine shown in the drawings incorporates oneembodiment of this invention and is of the two-cycle type having opposedcylinders in which two pistons l0 and II are arranged to reciprocate,the pistons being securely fastened together. These pistons are arrangedto reciprocate respectively in the cylinders [21 and I3 which, in theparticular construction shown, are made of relatively thin metal andprovided with integral heads l4. These cylinders are securely fastenedto an engine frame orhousing 15, which may be of .any suitable or usualconstruction, and which may be provided with intake passages or openingsl6, which register with corresponding openings I! in the cylinders l2and [3. The intake openings I6 and I! are preferably connected withsuitable means for supplying air under pressure to the cylinders at theends of theirpower strokes toscavenge the burnt gases from the pistons,and since such means are well known, they are not shown in the drawings.The engine frame is also provided with discharge or exhaust openings I9,which are in registration with exhaust openings 20 formed in the enginecylinders I2 and I3.

The engine cylinders with their integral heads are formed separatelyfrom the engine frame and may be of a different metal or alloy from thatof which the engine frame is made. The cylinders may be secured to theengine frame in any suitable or desired manner, and in the constructionillustrated, portions of the cylinders remote from the heads areprovided with screw threads 22. which engage correspondingly threadedportions of the engine frame. The engine cylinders may also be providedwith stop shoulders or flanges. 23 at which the threads terminate andwhich engage with shouldered portions of the engine frame to correctlyposition the cylinders on the engin frame.

As a result of this construction, it will be noted that the heads. ofthe cylinders and. large portions of the cylindrical walls thereof arespaced from the frame of the engine in such a manher as to providejackets 25 for a cooling fluid which may be circulated in any suitableor desired manner (not shown), and the engine frame may also be providedwith additional jackets 26 extending about the threaded portions of theframe and cylinders. Consequently, the portions. of the cylinders whichbecome heated to the greatest extent during the operation of the engineare entirely out of contact with the engine frame and are in directcontact with the cooling fluid.

The heads of the cylindersmay be provided with suitable threaded holesto receive spark plugs 28 and fuel injection nozzles 29, the latterreceiving fuel under pressure from a conduit or tube 30 connected withsuitable fuel supply means (not shown). The apertures in the cylinderheads for the spark plugs and fuel injection nozzles may be surroundedby annular flanges or bosses 3|, the purpose of which will be more fullyexplained. These bosses preferably have outer portions 32 of reduceddiameters.

It will be obvious that because of the mounting'of the cylinders l2 andI3, the outer or head portions of these cylinders will during theoperation of the engine become heated to a much greater extent than thewalls of the engine frame which surround these outer portions of thecylinders, and consequently, the cylinders will expand outwardly to agreater extent than the adjacent portions 34 ofthe engine frame whichextend about the outer portions of the cylinders. For this. reason, theopen ends of the portions 34' of the engine frame are provided withheads or closure disks which are sufliciently flexible to compensate forthe difference in expansion between the cylinders and the adjacent parts34 of the engine frame.

Any suitable flexible closures for the engine frame may be provided, andin the construction shown, I have provided closure disks 35 which aremade of relatively thin metal of a nature which will permit flexing ofthese disks to the extent required by the expansion and contraction ofthe cylinders. These disks are secured to the open endsv of the parts 34of the engine frame in any suitable manner, for example, by means ofbolts or screws 35, and gaskets 31 are provided to form fluid-tightconnections between the disks 35 and the parts'34 of the engine. Theclosure disks are provided with holes through -which the ends 3| of thebosses or flanges 30 can pass, and fluid-tight connections are providedbetween the disks 35 and these bosses'or flanges. This is done in theconstruction illustrated by screw threads on the parts 3| of thesebosses, with which nuts 38 cooperate, and suitable packing washers 39are provided which are compressed When the nuts 38 are tightened. Thedisks 35 of the engine frame may be provided with bulged out middleportions which ensure ample space between the cylinder heads l4 and thedisk 35 of the engine frame for the circula tion of cooling fluid. Sincethe closure disks 35 are only required to withstand the pressure of thecooling fluid circulated in the jackets of the engine, they can be madeof relatively thin material, which in turn facilitates the flexing ofthese disks.

The pistons l0 and H may be of any suitable or usual construction, thoseshown having their outer or head portions rounded or bulging to extendinto the correspondingly rounded or bulging head portions M of thecylinders. Each piston is preferably provided with means for deflectingair entering the inlet l6 toward the head of the cylinder, such forexample. as a grooved or recessed zone or part 42. at the peripheralportion of the head of the piston- This air deflecting grooverunctions'when the piston-is' in the exhaust position, as the one shownin the right hand side of Fig. 1, and results in'thoroughly scavengingthe burntgases' out'through the exhaust port l9, and prevents the airentering through the intake 16 from passing directly across the cylindertothe exhaust port 20. Any other means for acccmplishingthis result maybe employed.

The two pistons I l1 and l I are rigidly connected to each other in anysuitable manner. For example, inner portions of the pistons may beprovided with bifurcated extensions, each forming a pair of legs 43, theinner ends of which have flanges or lateral extensions 4'4 and 45, theadjacent end faces of which may besecured to each other. These flangesmay be providedon their end faces with interfitting shoulders 46 formedso that the two pistons will be positioned in correct relation to eachother. The flanges are provided with apertures through which bolts 41-may pass for securing the pistons together.

The bifurcated extensions of the pistons also receive between them theshaft 50 of the engine and these extensions of the pistons are,consequently, of suflicient length so that the pistons may reciprocatein their'cylinders without interfering with the centrally located shaft50 or the parts mounted thereon.

In order to provide access to the pistons and to the interior of theengine frame, this frame is provided at opposite sides thereof withholes or openings which are closed by means of suitable plates or.removable closure members 52 which may be bolted or otherwise secured tothe engine frame about the openings therein. These plates or closuremembers also provide bearings for the shaft 5|), the bearings beingformed by means of cylindrical portions or extensions 53 of the plates52'. The openings closed by the plates 52 are made of a size largeenough to permit the pistons to be inserted and withdrawn one at a time.In order to remove the pistons from the engine, the shaft 50 is firstremoved and the pistons are then separated :from each other by removingthe bolts 47. One of the pistons is then moved as far as possible towardthe head of its cylinder, and the other piston is moved partly into itscylinder and then turned about its axis through about 90 degrees so thatthe legs 43 of the bifurcated portion thereof can pass between the legs43 of the other piston, thus permitting the' first piston to be movedsidewise out of either one of the openings in the side of the engineframe or housing. The other piston is then withdrawn from its cylinderinto a position to be moved sidewise from the opening in the engineframe.

In order to transmit the motion of the pistons to the shaft, a pairofrocker arms 55 and 5.6 are provided which extend in opposite directionsfrom the shaft and which are mounted to oscillate about the axis of theshaft, the rocker arms being mounted on the shaft, one in advance of theother lengthwise of the shaft. The outer ends of these rocker arms maybe connected with the pistons in any suitable or desired manner, so thatthe straight line motion of the pistons is transferred to the rockerarms, the ends of which move in arcs of a circle. In the constructionshown, the legs 43 .of the bifurcated extensions of the pistons areslotted, as indicated at 51, to receive the rocker arms. The inner endsof the bifurcated extensions of the pistons or the legs 43 are providedat their meetin faces with registering semi-cylindrical recesses inwhich bearings 58 may be arranged for the end portions 59 of connectingor eccentric pins. cylindrical portions 60 which are eccentric withreference to the end portions 59 of the connecting pins. These largercylindrical portions BB are arranged in suitable bearings BI provided inthe ends of the rocker arms 55 and 56. By means of this construction,the straight line movement of the pistons may be converted intooscillatory swinging motion of the outer end of the connecting rods. Anyother means for transmitting motion of the pistons to the connectingrods may be employed.

The rocker arms 55 and 56 are intermittently connected with the shaft 50in such a manner that during the power stroke of the piston H], therocker arm 55 will be connected with the shaft 50. Since during thepower stroke of the piston ill, the piston ll passes through itscompression stroke, the other rocker arm 56 will be disconnected fromthe shaft 50. Similarly, when the piston H moves through its powerstroke, the rocker arm 56 will be coupled to the shaft 50 and the otherrocker arm 55 will be disconnected therefrom. Any suitable or desiredmechanism may be provided for this purpose, and one example of amechanism of this type will be described. To facilitate theunderstanding of this mechanism, the rocker arm 55 may be considered ascooperating with the piston l 0 and the rocker arm 56 as cooperatingwith the piston H.

In the operation of the engine as thus far described, it will be notedthat the pistons when starting through their power stroke transmit theirpower to the rocker arms while the same are at an angle of about 60degrees from what would be the dead center position in engines as nowcommonly constructed. Consequently, in such prior engines, the explosionin a, cylinder takes place approximately when the piston is in deadcenter position, and consequently, when the gas pressure in the cylinderis at its maximum,

the piston is still so near its dead center position that it is able todeliver comparatively little torque to the shaft, and most of thispressure and the shock resulting from the explosion must be absorbed andtaken by the crank shaft and These pins have bearings. Consequently, inengines as now commonly employed, when the maximum pressure is exertedon the piston, which is generally near the dead center position,comparativel little of this power-is converted into turning movement onthe crank shaft, and when the piston reaches a position at whichitspiston rod is nearly at a right angle to the crank, in which positionit can deliver the maximum torque to the shaft per unit of pressure inthe cylinder, this pressure in the cylinder has very materiallydecreased. By means of the construction shown in the drawings, however,the pistons never occupy positions anywhere near dead center withreference to the shaft 50, and consequently,.when a piston is sub jectedto the maximum pressure, a large proportion of this pressure isavailable for turning the shaft. For example, in Fig. l, the piston I0is in position to begin its power stroke and the explosive mixture inthe cylinder has been ignited. The force ten-ding to move the piston IDto the right in Fig. 1, consequently, delivers power to the rocker arm55 while the same occupies the position shown in Fig. 1, which is about30 degrees from a plane of the shaft 50 extending transversely of thepistons and the movement of the rocker arm 55 stops when the same hasswung to a, position 30 degrees at the opposite side of this plane.Consequently, in this engine, the dead center positions and allpositions located within degrees of the dead center position areeliminated, and the pistons thus act on the shaft in a highlyadvantageous manner so that a very efficient transmission of power fromthe pistons to the shaft results. While the rocker arms 55 in theconstruction illustrated in the drawings move through angles of 60degrees,it will be obvious that it is not intended to limit thisinvention to engines operating at angles of 60 degrees, since any angleof movement of the rocker arms may be provided, of which 360 degrees isthe multiple. It will be noted that, in the construction illustrated,for each revolution of the shaft, the pistons must make threereciprocations. 1

The mechanism herein illustrated by way of example for alternatelycoupling and uncoupling the rocker arms from theshaft is constructed topositively connect one of the two rocker arms to the shaft while onepiston is moving through its power stroke and for positivelydisconnecting this rocker arm from the pistons while this piston ismoving in the opposite direction, so that the rocker arms during thepower strokes of the pistons will each impart rotation to the shaft inthe same direction of rotation. In the construction shown for thispurpose, the rocker armsare connected to the shaft by means of gearswhich are locked against rotation while the rocker arm moves in adirection to transmit power to the shaft, and are released for turningwhen the rocker arm is moved in the reverse direction. For this purpose,the portion of each rocker arm which extends about the shaft is providedwith internal gear teeth which mesh with one or more pinions 66, threesuch pinions being shown in the drawings. These pinions are rotatablymounted in the shaft 59. For this purpose, the shaft 50 is preferablymade in two parts, which terminate near the longitudinal center line ofthe engine and the adjacent ends of these shafts are provided withannular enlargements 6! and 68. The peripheral portions of the flangesor en-v largements 61 and 68 are recessed to receive the portions of therocker arms 55 and 56 which extend; about the shaft, and to. space theserocker arms from eachother, I preferably employ a spacer or partitionplate 69 which is placed between the adjacent ends of the flanges orenlargements and the peripheral portions of which extend between the tworocker arms 55 and 56. End thrust bearing rings 69a are preferably provided at. the outer faces of the annular portions of the rocker arms 55and 56. Any suitable means may be provided for connectingthe two flangesor enlargements of the two partsof the shaft 50, such for example: asbolts or screws It, and one of the two parts of the shaft 50 ma beprovided with a central or axial stud or integral projection 12. whichextends into. an accurately formed axial hole in the other part of theshaft, so; that the; two parts of the shaft will be accuratelyalinedaxially.

The, pinions 55 are provided with shafts 14 which are suitablyjournalled in. the flanges til and 68 of the shaft, for example, in.bearings 15 formed in these flanges, one set of pinions being providedfor each flange. Preferably, additional bearingv supports are provided.for the pinions, this being done by means of bearing studs 16, Fig. 5,.which are preferably secured to the spacing plate or disk 69 and thesestuds enter into holes bored-coaxially into. the shafts. 4 with thepinions 66. The pinions 66 are preferably arranged in pairs which are inaxial ali-nement with each other, one pinion of each pair meshing withthe internal gear, teeth of one. of the rocker arms, and, the otherpinion cooperating with the other rocker arm, and consequently, eachstud i may enter into the adjacent ends of tWo pinions, one of. whichpinionsis journalled in theflange 6? the other pinion being journalledin the flange $8.

The outer ends of the shafts 14 connected with the pinions B6 areprovided, with cams 13 which, in, thev construction shown, are integralwith the pinions and their shafts l and these cams are arranged tocooperate with stationary cam plates 80 which, in, the constructionshown, ar secured to thestationary closure members 52-of the engineframe, for example, by means of bolts or screws 8!. These. stationarycams have cylindrical portions 82 which are concentric with the shaft 50and between these cylindrical portions of the. cams are recesses 83extending inwardly from the. inner peripheries of the cams. As clearlyshown in Figs. 6 to 8, the cam portions 18 of the pinion shafts 14 areeach provided with one face. 84 which has, substantially the same radiusof curvature as the cylindrical portions 82 of the cam plate 80., sothat the. face 84 of each pinion cam 18 may engage with the cylindricalportions 82 .of the stationary cam plate 80 and slide along thesesurfaces 82. It will be obvious that when. the cam faces 84 and 82 arevin sliding engagement, the pinions 66 will be held against rotationabout their own axes, and when so held, the rocker arm connected withthese pinions is coupled to the shaft 50 so as to transmit power theretofrom an engine piston, or if the engine is being started or cranked byturning the shaft 58, power will be transmitted from the shaft to thepistons.

When the cam portion 18 of thepinion shafts move into positions at thecut-out portions 83 of the stationary cam plateBU, it will be obviousthat the cam portions 78 then release their pinions 66, so that the samemay rotate about their axes and this rotation causes the cam portions l8of the piston shafts to swing into the recessed ortions 83 ofthestationary cams indica ed positioned relatively to the other stationarycam that when one set of pinions is held, against. rotation by thecylindrical portion 82 of one cam plate 80, the other set. of pinions isfree. to: r0.- tate in a. recessed portion 83 of the other Stationarycam. In other words, when the pinion cams 18 of one set of pinionsgeared to rocker arm 55 are in sliding contact with the cylindricalportions 82 of one stationary cam plate so that these pinionsv are heldagainst rotation, the other set. of pinions geared to the other rockerarm 56 willbe free to, rotate, since their cams, 18 will have, slid.along the. cylindrical portions 82; 0f the cam plate so. as to be in,the recessed portions 83 of th other stationary cam. It will,consequently, be obvious that one of the two rocker arms 55v and 56will. alwaysbe coupled to the. shaft 51!, so that in theparticul'arconstruction illustrated, in which the rocker arms swing, in,v arcs of,60 degrees, each reciprocation 0f the pistons advances the shaft through120 degrees.

- The cam fac 86 of the pinion shaft is preferably also provided with acam groove or depres. sion 8.? which extends rearwardly from the axis ofrotation 88 of the pinion shaft, see, Fig. 8. This cam groove 87? is soformed thatfas the cam member is swings out of a recessed portion. 83,of the stationary cam 89, the edge portion 89. 0f the stationary camremain in contact with the surface of the cam groove until the camsurface 84 contacts with the concentric or cylindrical face 82 of thestationary cam. represents the axis of the shaft 58 in Fig. 8.

-In the operation of the mechanism described, it will be noted that as arocker arm begins its return swing during the compression stroke, of itspiston, the cams T8 of the three pinion shafts con, nected with thisrocker arm begin their rotation Within the recesses 83, As the rockerarm approaches the end of its compression swing, the edge portion 89 ofthe stationary cam enters the groove 81 before this swing of the rockerarm is completed. If there should be a tendency of the piston not toreturn to its outermost position, or in other Words, if the piston tendsto, stop before it has, reached the intended end of its compressionstroke, then pressure will be exerted by the edge portion. 89 against aportion of the groove 8.! to turn the cam 18 into position to have itsface 84 lie on the cylindrical face 82, of the stationary cam. Thispressure willincrease as the edge 89 engages parts. of the groove 81further removed from the center of rotation 88 of the pinion shaft andwill force. the piston into its outermost position. If the piston tendsto move beyond this position, then it will be stopped at its outermostposition by the engagement of the face 34 of the cam 78 with thecylindrical portion 82 of the stationary cam. Other means for couplingand uncoupling. the. rocker arms, to and from the shaft may be provided.I

The engine may be lubricated in any desired manner, no lubricating meansbeing shown in the drawings. Also any suitable means may be provided fordirecting'a cooling, fluid, through the jackets of the engine and forcooling any parts of the engine requiring cooling, such means being.

omitted from the drawings to avoid confusion.

By means of the mechanism described, it will be obvious that the pistonswill at all times be coupled to the shaft either through the rocker arm55 or through the rocker arm 56, and. this coupling is positive so thatthe shaft 50 may be rotated for the purpose of starting or cranking theengine, and so that the shaft 50 will atall times be in synchronism withthe pistons. This ensures the positive stroke of each piston so thatuniform compression will result, Another advantage of this arrangementis that the timing mechanisms for fuel injection, ignition, etc., may bedriven from the engine shaft, as has heretofore been customary inconnection with crank shaft engines.

The engine described has the advantage that power generated in thecylinders by the combustion of the fuel will be transmitted to the shaft50 much more efficiently than in engines heretofore in general use. As aresult of this construction, a relatively short stroke may be employed,and the movement of the pistons will be more responsive to the pressuresof the burning gases, since movement of the pistons will not be delayedby the crank shaftrpositions at and near dead center. The more rapidtravel of the pistons and the shorter stroke will result in thedischarge of the burned gases more rapidly so that less of the heat willbe transmitted to the parts of the engine. As a result of these variousfeatures, the engine herein described is more efficient than engines ofthe type now commonly used.

It will, of course, be obvious that the coupling and uncouplingmechanisms herein described may be used in connection with engines ofdifferent construction from the one herein illustrated.

V I claim as my invention:

1. An engine including a pair of oppositely disposed pistons rigidlyconnected with each other, a shaft, a pair of rocker arms extending inopposite directions from said shaft and each having one end thereofmounted to oscillate about said shaft and having the other end connectedto said pistons, means for coupling one of said rocker arms to saidshaft during the power strokes of one of said pistons and for couplingthe other rocker arm to said shaft during the power stroke of the otherpiston, and means for uncoupling said rocker arms from said shaft duringthe compression strokes of their pistons,

2. An engine including a pair of oppositely disposed pistons havingtheir adjacent ends bifurcated and secured together, a shaft extendingthrough said bifurcated ends of said pistons, rocker arms mounted toswing about said shaft and extending in opposite directions therefromand having their outer ends connected with said pistons, and couplingmeans for alternately coupling and uncoupling said rocker arms to saidshaft, one rocker arm being coupled to said shaft when said pistons movein one direction and the other rocker arm being coupled to the shaftwhen said pistons move in the other direction.

' 3. An engine having oppositely disposed pistons and provided at theiradjacent portions with oppositely spaced legs, means for securing thelegs of one piston to the legs of the other piston for rigidly securingsaid pistons to each other, a shaft extending between the legs of saidpistons, arms extending in opposite directions from said shaft andconnected with said pistons to cause the reciprocatory motion of saidpistons to alternately swing said arms in opposite directions about saidshaft and in opposite directions to each other, and means foralternately coupling said arms to said shaft and uncoupling said armsfrom said shaft, one of said arms being coupled to the.

shaft while the other arm is uncoupled therefrom. 4. An engine havingoppositely disposed pistons and provided at their adjacent portions withoppositely spaced legs, means for securing the legs of one piston to thelegs of the other piston for rigidly securing said pistons to eachother, a shaft extending between the legs of said pistons, armsextending in opposite directions from said shaft and connected with saidpistons to cause the reciprocatory motion of said pistons to alternatelyswing said arm in opposite directions about said shaft and in oppositedirections to each other, and means for coupling said arms to saidsh'aft when they move in the direction of rotation of said shaft and foruncoupling said arms from said shaft when they move in the oppositedirection.

5. An engine having oppositely disposed pistons and provided at theiradjacent portions with oppositely spaced legs, means for securing thelegs of one piston. to the legs of the other piston for rigidly securingsaid pistons to each other, a shaft extending between the legs of saidpistons, rocker arms arranged about said shaft, one of said rocker armsbeing connected with said piston at one side of said shaft and th'eotherrocker arm being connected with said piston at the other side of saidshaft, to cause reciprocation of said pistons to swing said arms aboutsaid shaft, and means for operatively connecting one of said arms tosaid shaft during the power stroke of one piston and for operativelyconnecting the other arm to said shaft during the power stroke of theother piston, said means disconnecting said arms from said shaft whentheir pistons move in their compression strokes.

6. An internal combustion engine having opposed cylinders, a, piston ineach cylinder, said pistons being secured to each other, a shaft locatedintermediate of said pistons, and two connections between said shaft andsaid pistons, one connection being coupled with said shaft during thepower stroke of one piston and the other connection being connected withsaid shaft during the power stroke of said other piston, saidconnections being uncoupled from said shaft when their pistons movethrough their compression strokes, and turning said shaft through lessthan one-half revolution during each power stroke.

7. An internal combustion engine including a frame, a pair of opposedcylinders mounted on said frame, pistons arranged to reciprocate insaid-cylinders and having the ends adjacent to each other bifurcated toform a pairof legs on each piston, means for securing said legstogether, a shaft extending between said legs, a driving connectionbetween said pistons and said shaft, said frame being provided withopenings at opposite sides thereof, and closure members removablysecured to said frame for closing said openings and having, bearings forsaid shaft.

8. An internal combustion engine including a frame, a pair of opposedcylinders mounted on said frame, and having heads formed integraltherewith, pistons arranged to reciprocate in said cylinders and havingthe ends adjacent to each other bifurcated to form a pair of legs oneach piston, means for securing said legs together, a shaft extendingbetween said legs, a driving connection between said pistons and saidshaft, said frame being provided with openings at opposite sidesthereof, of sufficient size to permit said pistons when separated fromeach other to be removed th'rough said openings, and closure membersremovably secured to said frame for closin coupling means alternatelypositively connecting and disconnecting said arms from said shaft totransmit movement of the pistons to said shaft, whereby turning of saidshaft produces reciprocatory movement of said pistons.

10. In an internal combustion engine, the combination of a pair ofopposed pistons, said pistons having legs at the portions adjacent toeach other and which are secured together't'o rigidly connect saidpistons with each other, a shaft extending into said frame and passingbetween said legs, a pair of rocker arms arranged to oscillate aboutsaid shaft, one of said rocker arms extending from one side of saidshaft and being connected for cooperation with one or said pistonsandthe other rocker arm extending from the other side of said shaft andbeing connected for codperationwith the other piston for oscillation ofsaid rocker armsby the reciprocation of said pistons, and a cam actuatedmechanism for alternately coupling said rocker arms to said shaft andfor simultaneously coupling one rocker arm and uncoupling the otherrocker arm, for transmitting power from said pistons "to said shaft.

'11. 'The' combination with an :internal combustion engine havingopposed 'reciprocatory pistons having spaced legs secured to each other,a shaft extending between said spaced legs, a pair of rocker armsinbunted to oscillate about said shaft and extending 'froi'n -oppositesides of said shaft and cdnheoted'with said pistons for oscillation ofsaid rocker arms by said pistons, gears on said'reeksr arms concentricwith 'saidsha'ft, pinions iournaued onsaid shaft and meshing with saidgears, and means'for alternately stoppin the rotation of said pinionsabout their axes and re1easi'ng them "for said rotation, the pinionsdrivenby one ro'ciker arm being held against said rotation while one orsaid lpist'ons is moving throu h its power stroke and the "pinionsdriven by the other rocker arm being "held against rotation when theother piston is'moving through its power stroke, to transmit power 'fremsaidfrocker arms through said gears and pinions to said shaft during thepower strokes of said pistons.

12. The combination with an internal combustion engine having opposedre'ciproc'atory pistons having spaced legs secured to each other, ashaft extending'betweensaid spaced legs, a pair of rocker arms mounted'to-oscillate about said shaft and extending from opposite sides of saidshaft and connected with said pistons for oscillation of said rockerarms by said pistons, a gear fixed on each rocker arm, a pinionjournalled on said shaft and meshing with one of said gears, and anotherpinion journalled on said shaft and meshing with the other gear, meansfor locking the pinion connected with one of said rocker arms againstrotation while the pinion connected with the other rocker arm is free torevolve and while one of said pistons is moving through its powerstroke, and means for reversing .the locking and releasing of saidpinions while the other piston islmoving through its power stroke,whereby sai'dpistons are at'all times positively connected in .drivingrelation to saidjshaftgthrough said pinions when locked.

1 3."The combination with an internal combustion engine having opposed're'ciprocatory pistons havmg spaced legs secured to each "other, ashaft extending between said. spaced legs, a pair or rocker arms mountedto oscillate about said shaft and extending from opposite sides ofsaids'lraft and connected with saidpistons for oscillation of saidrocker arms by said pistons, gears fixed on said rocker arms, pinionsj-ournalled on said shaft, one of said pinions meshing with th'e gear ofone rocker arm and the other ,pinion meshing with the gear of the otherrocker 'arm, cams cooperating with said pinions 'for alternately holdingsaid pinions against rotation about their axes'andfor releasing saidpinions to rotate about their axes, said cams being timed to cause onepinion to be locked while the other is released, a pinion being lockedWhile therocker arm conneoted therewith is actuated by the power strokeof one piston and the other pinion being locked while the other arm isactuated by the power stroke of the other piston.

14. The combination with an internal combustion engine having opposedreciprocatory pistons having spaced legs secured to each other, a shaftextending between said spaced legs, a pair of rocker arms mounted tooscillate about said shaft and extending from opposite sides of saidshaft and connected with said pistons for oscillation of said rockerarms by said .pistons, said rocker arms being provided with internalgear teeth arranged in fixed relation thereto, pinions journalled onsaid shaft in eccentric relation thereto, one of said pinions meshingwith the teeth of one rocker arm, and the other pinion meshing with theteeth of the other rocker arm, and cam means for alternately locking onepinion against rotation about its axis while the other pinion is free torotate about its axis, said cam means being timed .to lock the pinionconnected with one rocker arm againstrotation While one of said pistonsmoves through its power stroke and for locking the other pinion againstrotation when the other piston moves through its power stroke, wherebysaid rocker arms are alternately coupled to said shaft through said gearteeth and pinion. 7

15. The combination with an internal combustion engine having opposedreciprocatory pistons having-spaced legs secured to each other, a shaftextending between said spaced legs, a pair of rocker arms mounted tooscillate about said shaft and extending from opposite sides of saidshaft and connected with said pistons for oscillation of said rockerarms by saidpistons, each of said rocker arms having agear fixedthereto, pinions journalled on said shaft, in eccentric relationthereto, one'of said pinions meshing with'the gear of one of said rockerarms, and the other pinion meshing with the gear of .the other rockerarm, a cam arranged in fixed relation to each of said pinions to rotatetherewith, a pair of stationary cams, one of which cooperates with thecam of one of said pinions and the other of which :00- operates with thecam of the other pinion, said stationary and pinion cams operating tointermittently lock said pinions against rotation about their axesandftorelease said pinions for rotation about their axes, said cams beingtimed to lock the pinion connectedwith one of-said arms While one ofsaid pistons moves through its power stroke an dto lock'theoth e'rpinion against rota tion "while the other piston movesthrough it'sp'dweristroke; V j j 16. An internal combustionengine havin'g'opthereinand secured to each other, a rotary shaft,

a pair of arms arranged to swing about said shaft and extending inopposite directions therefrom and connected with said pistons to convertreciprocatory motion of said pistons to oscillatory swinging motion ofsaid arms, each of said arms having a gear arranged in fixedrelationthereto, pinions journalled on said shaft to rotate about axesspaced from the axis of rotation of said shaft, one pinion meshing withone gear of one of said arms and the other pinion meshing with the gearof the other arm, each pinion having a cam rotatable therewith, a, pairof fixed cams, one of said cams cooperating with the one of said pinionsand the other cam cooperating with the other pinion, the faces of saidstationary cams and of the pinion cams cooperating therewith beingformed to hold said pinions against rotation about their axes while thearms geared thereto are moved by the power strokes of the pistons and topermit rotation of said pinions while the arms geared thereto are movedby the compression strokes of said pistons, and additional faces on saidstationary and fixed cams which engage during rotation of said shaft, torotate said pinions during the final portion of the movement of saidpistons in their compression strokes in a direction to move said pistonsthrough said portions of their compression strokes.

17. An internal combustion engine having opposed cylinders, pistonsarranged to reciprocate therein and secured to each other, a rotaryshaft,

a pair of arms arranged to swing about said shaft and extending inopposite directions therefrom and connected with said pistons to convertreciprocatory motion of said pistons to oscillatory swinging motion ofsaid arms, each of said arms having a gear arranged in fixed relationthereto, pinions journalled on said shaft torotate about axes spacedfrom the axis of rotation of said shaft, one pinion meshing with thegear of one of said arms and the other pinion meshing with the gear ofthe other arm, each pinion having a cam rotatable therewith, a pair offixed cams, one of said cams cooperating with one of said pinions andthe other cam cooperating with the other pinion, the faces of saidstationary cams and of the pinion cams cooperating therewith beingformed to hold said pinions against rotation about their axes while thearms geared thereto are moved by the power strokes of the pistons, andto permit rotation of said pinions while the arms geared thereto aremoved by the compression strokes of said pistons, a cam groove on eachpinion cam arranged near and at one side of the axis of rotationthereof, and a projection on each stationary cam which enters said camgroove during the final rotation of the pinion cam to exert pressure onthe pinion cam in a direction to positively force the pinion to completeits rotation and thereby ensure the movement of the piston connectedtherewith to the end of its compression stroke.

I JOSEPH S. PARENTI.

